Frankie Dettori may yet recover his licence in time to ride at Epsom's Classic meeting this weekend but it appears he will play no part in the Derby itself. His hopes for that race had rested with the possibility of a ride on one of Aidan O'Brien's many runners but the Ballydoyle trainer revealed his plans on Wednesday night without naming the Italian.

Speculation linking Dettori with O'Brien appeared entirely legitimate as the jockey rode Camelot for the Irishman in last year's Prix de l'Arc de Triomphe, shortly before the jockey was handed a six-month ban for a positive cocaine test taken the previous month. Dettori had also ridden work at O'Brien's yard on more than one occasion in recent weeks.

But the trainer never once commented directly on the subject. Each year, riding plans for his Derby runners appear to be settled just three or four days before the race and on this occasion O'Brien's team was reduced by one at the same time, as he decided against sending over Magician, winner of the Irish 2,000 Guineas last Saturday.

"While he came out of his win at the Curragh very well, it is a long season," O'Brien said in quotes reported on the Racing Post website. "We will train him for the St James's Palace Stakes."

The trainer's son Joseph will ride Battle Of Marengo, long thought to be the stable's No1 Derby contender. Ryan Moore will be on Ruler Of The World, having won the Chester Vase on him.

Richard Hughes has apparently come in for the ride on Mars, a horse he has never ridden before. Hughes was third in the 2009 Derby on the O'Brien-trained Masterofthehorse, a 16-1 shot. O'Brien's challenge is rounded out by Festive Cheer, to be ridden by Seamie Heffernan, and Flying The Flag, who will be partnered by Colm O'Donoghue.

There may have been a place for Dettori if Magician had been in the line-up, or if Telescope had been fit to run, in which case Moore would have been required for him. But it may also be that the partners in Coolmore, O'Brien's employers, were reluctant to sign up Dettori for such an important occasion on what will be, at best, his second day back after being on the sidelines for half a year.

Dettori hopes to be given the all-clear from France at some point on Thursday afternoon, once the final set of results are available from tests he has taken there in the past week. The British Horseracing Authority has offered assurances that Dettori will be able to ride in Britain as soon as the French authorities pass him fit, but his agent has given up hope of him riding at Epsomon Friday . "As far as I'm concerned, Friday's gone," said Ray Cochrane on Wednesday . They're talking about the BHA making some concession," he added, sounding less than convinced. "I can't worry about that. We'll just carry on when he is licensed.

"He's missed six months, so another day or two won't do too much harm. It would have been a Group One day and we had five rides sorted out, but anyway …"

Nonetheless, there were indications on Wednesday night from others in Dettori's entourage that the Italian still hopes to ride on Friday , perhaps even in the Oaks itself. As for Saturday's card, Cochrane reports opportunities to be "very tight. If he ends up getting two or three rides, that's it".